just average human-like ears
apparent at birth
(excluding flightless bird species, emu, ostrich, penguin, dodo, penguin, cassowary, ect)
vary from small-medium-large
wings aren't fully developed until early adolescense
Feather color is limitless and based off any real bird species
two Harpy of the same bird species can have completely different feather coverage on the body
General shapes(Varys by species of bird)
examples
Raptor: eagles, hawks, owls, falcons,ect birds of prey
Webbed: ducks, swans, geese, ect water fowl
Perching: Songbirgs, Crows, Pigeons, Parrots, ect
Walking: Chickens, Peacocks, pheasants, ect land fowl
Flightless: Emu, Cassowary, Dodo, ect
Flightless(webbed): Penguins